U.S. patent number 6,358,234 [Application Number 08/908,828] was granted by the patent office on 2002-03-19 for absorbent article having deformed hinge and zones of extensibility.
This patent grant is currently assigned to The Procter & Gamble Company. Invention is credited to Jeffrey Vincent Bamber, Shirley Lee Chow, Robb Eric Olsen, Nami Terada.
United States Patent |
6,358,234 |
Terada , et al. |
March 19, 2002 |
**Please see images for:
( Certificate of Correction ) ** |
Absorbent article having deformed hinge and zones of
extensibility
Abstract
Absorbent articles such as sanitary napkins, panty liners, adult
incontinence devices, and the like, which have flaps are disclosed.
The absorbent articles have a deformed hinge that is located
between at least a portion of the main body portion of the
absorbent article and the flaps, and zones of extensibility for
relieving the stresses that develop in the flaps when the flaps are
folded down and under a wearer's undergarment.
Inventors: |
Terada; Nami (Nada-ku,
JP), Olsen; Robb Eric (Cincinnati, OH), Chow;
Shirley Lee (Cincinnati, OH), Bamber; Jeffrey Vincent
(Cincinnati, OH) |
Assignee: |
The Procter & Gamble
Company (Cincinnati, OH)
|
Family
ID: |
27578170 |
Appl.
No.: |
08/908,828 |
Filed: |
August 8, 1997 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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539915 |
Oct 6, 1995 |
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253001 |
Jun 2, 1994 |
5620430 |
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073256 |
Jun 4, 1993 |
5389094 |
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469891 |
Jan 23, 1990 |
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539915 |
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230454 |
Apr 21, 1994 |
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042840 |
Apr 5, 1993 |
5354400 |
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769607 |
Oct 1, 1991 |
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539915 |
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096121 |
Jul 22, 1993 |
5584829 |
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493515 |
Jun 22, 1995 |
5891121 |
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Current U.S.
Class: |
604/385.04;
604/387 |
Current CPC
Class: |
C07F
7/1804 (20130101); C07C 271/22 (20130101); C07K
5/021 (20130101); C07K 7/02 (20130101); A61F
13/472 (20130101); A61F 13/47227 (20130101); A61F
13/47263 (20130101); A61F 13/476 (20130101); A61F
13/51466 (20130101); A61F 13/515 (20130101); A61F
13/535 (20130101); A61F 13/5616 (20130101); A61F
13/511 (20130101); A61F 2013/530007 (20130101); A61F
2013/530226 (20130101); A61F 2013/530328 (20130101); A61F
2013/530335 (20130101); A61F 2013/530481 (20130101); A61F
2013/530547 (20130101); A61F 2013/530583 (20130101); A61F
2013/530802 (20130101); A61F 2013/530875 (20130101); A61F
2013/53908 (20130101); A61F 2013/53916 (20130101); A61F
2013/53925 (20130101); A61F 2013/5395 (20130101); A61F
2013/53966 (20130101); A61F 2013/53975 (20130101); A61F
2013/586 (20130101); A61K 38/00 (20130101); A61F
13/475 (20130101); A61F 13/49009 (20130101); A61F
13/491 (20130101); A61F 13/51 (20130101); A61F
13/53 (20130101); A61F 13/537 (20130101); A61F
2013/15365 (20130101); A61F 2013/15373 (20130101); A61F
2013/15382 (20130101); A61F 2013/1539 (20130101); A61F
2013/4708 (20130101); A61F 2013/49023 (20130101); A61F
2013/49031 (20130101); A61F 2013/49033 (20130101); A61F
2013/49042 (20130101); A61F 2013/49044 (20130101); A61F
2013/49046 (20130101); A61F 2013/5055 (20130101); A61F
2013/51066 (20130101); A61F 2013/51409 (20130101); A61F
2013/51429 (20130101); A61F 2013/530131 (20130101) |
Current International
Class: |
C07K
7/00 (20060101); C07F 7/18 (20060101); C07K
7/02 (20060101); C07C 271/00 (20060101); A61F
13/56 (20060101); A61F 13/15 (20060101); C07C
271/22 (20060101); C07K 5/02 (20060101); C07F
7/00 (20060101); C07K 5/00 (20060101); A61K
38/00 (20060101); A61F 013/15 () |
Field of
Search: |
;604/385.1,385.2,386,387,389,390,385.01,385.04,385.03 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 335 527 |
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Apr 1989 |
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EP |
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0 337 438 |
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Oct 1989 |
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EP |
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0 426 235 |
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May 1991 |
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EP |
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0 446 818 |
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Sep 1991 |
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EP |
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0 467 184 |
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Jan 1992 |
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EP |
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0 511 905 |
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Nov 1992 |
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Jun 1986 |
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40-36391 |
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Dec 1965 |
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JP |
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236101 |
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Oct 1993 |
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NZ |
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WO 92/07528 |
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May 1992 |
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WO |
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WO 92/07535 |
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May 1992 |
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WO |
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WO 93/01785 |
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Feb 1993 |
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WO |
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WO 93/01786 |
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Feb 1993 |
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WO |
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WO 93/06805 |
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Apr 1993 |
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WO |
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WO 94/02096 |
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Feb 1994 |
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WO |
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WO 95/03023 |
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Feb 1995 |
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WO |
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WO 95/03025 |
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Feb 1995 |
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WO |
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WO 95/03765 |
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Feb 1995 |
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WO |
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WO 95/07675 |
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Mar 1995 |
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WO |
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WO 95/08311 |
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Mar 1995 |
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WO |
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Primary Examiner: Ruhl; Dennis
Attorney, Agent or Firm: Hickman; Ingrid N. Cummings;
Theodore P. Johnson; Kevin C.
Parent Case Text
This is a continuation of application Ser. No. 08/539,915, filed on
Oct. 6, 1995, now abandoned, which is a continuation-in-part of the
following applications: application Ser. No. 08/253,001, filed Jun.
2, 1994, now U.S. Pat. No. 5,620,430, which is a division of
application Ser. No. 08/073,256, filed Jun. 4, 1993, now U.S. Pat.
No. 5,389,094, which is a continuation of application Ser. No.
07/469,891, filed Jan. 23, 1990 (now abandoned); application Ser.
No. 08/230,454, filed Apr. 21, 1994 (abandoned), which is a
division of application Ser. No. 08/042,840, filed Apr. 5, 1993,
now U.S. Pat. No. 5,354,400, which is a continuation of application
Ser. No. 07/769,607, filed Oct. 1, 1991(now abandoned); application
Ser. No. 08/096,121 filed Jul. 22, 1993, now U.S. Pat. No.
5,584,829; and application Ser. No. 08/493,515 filed Jun. 22, 1995,
now U.S. Pat. No. 5,891,121.
Claims
What is claimed is:
1. An absorbent article for wearing in a crotch region of an
undergarment, said crotch region having a pair of side edges, said
absorbent article having a liquid pervious body-facing side, a
liquid impervious garment side, a principal longitudinal centerline
extending in a longitudinal direction, and a principal transverse
centerline extending in a transverse direction, said absorbent
article comprising:
a main body portion having a central region, two spaced apart
longitudinal side edges and two spaced apart end edges, said main
body portion comprising an absorbent core positioned between said
body-facing side and said garment side;
a pair of flaps for folding around the side edges of the crotch
region of undergarment, said flaps being joined to said main body
portion, each flap extending laterally outward along one of the
longitudinal side edges to a distal edge, said flaps each having a
flap transverse centerline that passes through said central region
of said main body portion;
a deformed region comprising a portion of said absorbent article
that has planar portions and at least some portions that are
displaced in a direction perpendicular to said planar portions,
wherein said deformed region is substantially free of overlapping
portions, and said deformed region forms a hinge between said main
body portion and said flaps; and
at least one zone of extensibility comprising at least a portion of
at least one of said flaps, wherein at least a portion of said zone
of extensibility is spaced longitudinally away from said flap
transverse centerline.
2. The absorbent article of claim 1 wherein a portion of said flaps
outboard of said distal boundary of said composite region is a
generally semi-circular area that is substantially planar and is
stiffer than said composite region.
3. The absorbent article of claim 2 wherein said generally
semi-circular portion of said flaps has a fastener thereon.
4. The absorbent article of claim 1 wherein said hinge has a
pre-formed distal boundary spaced apart from said proximal boundary
which is also concave relative to the distal edge of said flap.
Description
FIELD OF THE INVENTION
The present invention relates to absorbent articles such as
sanitary napkins, panty liners, adult incontinence devices, and the
like. Still more particularly, the present invention concerns
absorbent articles such as sanitary napkins, and the like having
flaps with a deformed hinge and zones of extensibility for
relieving the stresses that develop in the flaps when the flaps are
folded down and under a wearer's undergarment.
BACKGROUND OF THE INVENTION
Absorbent articles, particularly sanitary napkins, having wings or
flaps are disclosed in the patent literature and are available in
the marketplace. Sanitary napkins having flaps of the various types
are disclosed in U.S. Pat. No. 4,687,478, entitled "Shaped Sanitary
Napkin With Flaps", which issued to Van Tilburg on Aug. 18, 1987,
U.S. Pat. No. 4,608,047, entitled "Sanitary Napkin Attachment
Means", which issued to Mattingly on Aug. 26, 1986, U.S. Pat. No.
B1 4,589,876, entitled "Sanitary Napkin", which issued to Van
Tilburg on May 20, 1986, U.S. Pat. No. 4,285,343, entitled
"Sanitary Napkin", which issued to McNair on Aug. 25, 1981, U.S.
Pat. No. 3,397,697, entitled "Disposable Sanitary Shield For
Undergarments", which issued to Rickard on Aug. 20, 1968, and U.S.
Pat. No. 2,787,271, entitled "Sanitary Napkin", which issued to
Clark on Apr. 2, 1957.
A number of variations on the types of flaps described above have
been presented in an attempt to solve various problems. U.S. Pat.
No. 4,900,320 issued to McCoy on Feb. 13, 1990, discloses a
sanitary napkin having flaps affixed at points inward from the
longitudinal edge of the napkin. U.S. Pat. No. 4,911,701 issued to
Mavinkurve on Mar. 27, 1990, discloses a sanitary napkin having
elastic means for providing greater convex shape to the body-facing
portion of the central absorbent and for enabling adhesive-free
placement of the flaps of the napkin. U.S. Pat. No. 4,940,462
issued to Salerno on Jul. 10, 1990, discloses a sanitary napkin
with longitudinally expandable flaps. A sanitary napkin having
flaps with stress relief means in the form of a notch or a slit is
described in U.S. Pat. No. 4,917,697 which issued to Osborn, III,
et al. on Apr. 17, 1990. U.S. Pat. No. 5,389,094 issued to Lavash
et al. on Feb. 14, 1995, discloses sanitary napkins (and other
types of absorbent articles) having flaps and zones of differential
extensibility. Although these latter sanitary napkins work quite
well, the search for sanitary napkins that are more cost effective,
as well as those which have improved flaps has continued.
SUMMARY OF THE INVENTION
In accordance with the present invention, an absorbent article,
such as a sanitary napkin, is provided. The sanitary napkin has
flaps with a deformed hinge and zones of extensibility for
relieving the stresses that develop in the flaps when the flaps are
folded around and under the edges of the crotch of the wearer's
panties.
The sanitary napkin has a principal longitudinal centerline and a
principal transverse centerline. The sanitary napkin comprises a
main body portion and a pair of flaps joined to the main body
portion. The main body portion of the sanitary napkin comprises a
liquid pervious topsheet, a liquid impervious backsheet joined to
the topsheet, an absorbent core positioned between the topsheet and
the backsheet. The main body portion has two spaced apart
longitudinal edges and two spaced apart transverse end edges.
The flaps are each joined to the main body portion at a juncture.
The flaps extend laterally outward from at least a central region
of the main body portion beyond the longitudinal side edges of the
main body portion. In one preferred embodiment, the flaps are
integral extensions of the topsheet and backsheet. The flaps are
divided into a front half and a back half by a flap transverse
centerline. The flaps each have two corner regions which are
located adjacent the area of the ends of the junctures of the flaps
with the main body portion. One corner region is located adjacent
the area of the juncture in each direction remote from the
principal transverse centerline. The sanitary napkin comprises a
deformed hinge (or bending zone) located in a region that includes
the juncture of the flaps with the main body portion and zones of
differential extensibility in the corner regions of the flaps. The
deformed hinge provides at least one axis about which the flaps may
fold relative to the main body portion. The zones of differential
extensibility allow the corner regions to extend outward
(preferably in a generally transverse direction) to provide a means
for the relief of stresses that develop in the flaps of the
sanitary napkin when the sanitary napkin are folded down and under
a wearer's undergarments.
In an alternative embodiment, at least a portion of the deformed
hinge comprises a portion of the sanitary napkin which has a
strainable network formed therein. The strainable network comprises
at least two visually distinct regions. The network is configured
so that at least one of the regions, the second regions, have a
surface-pathlength (dimension measured along the surface) which is
greater than that of the other regions, the first regions. The
second regions exhibiting the longer surface-pathlength preferably
comprise one or more rib-like elements. The first regions with the
shorter surface-pathlength are preferably substantially planar. In
this embodiment, the portion of the deformed hinge comprising this
type of strainable network is preferably located at least in the
region of the flap transverse centerline.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a preferred sanitary napkin embodiment
of the present invention.
FIG. 2 is a lateral cross-sectional view taken along line 2--2 of
FIG. 1 through the corner region of one of the flaps of the
sanitary napkin.
FIG. 3 is a lateral cross-sectional view taken along line 3--3 of
FIG. 1 through the center portion of one of the flaps.
FIG. 4 is a perspective view of the crotch portion of a woman's
panties with the sanitary napkin shown in FIGS. 1-3 in place
therein.
FIG. 5 is a top plan view of a web material having a strainable
network of the type used in the deformed hinge of the sanitary
napkin shown in FIGS. 1-3, the web material being shown in a
substantially untensioned condition.
FIG. 6 is an enlarged segmented perspective illustration of the web
material shown in FIG. 5 in which the web material is in a
substantially untensioned condition.
FIG. 7 is an enlarged segmented perspective illustration of the web
material shown in FIG. 5 in which the web material is subjected to
tension in an amount which is sufficient for a substantial portion
of the deformations of the web material to enter the plane of
applied elongation.
FIG. 8 is an enlarged segmented perspective illustration of the web
material shown in FIG. 5 in which the web material is in a
condition in which it will exhibit a second stage of resistive
forces to elongation.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to absorbent articles that are worn
in an undergarment, such as sanitary napkins, panty liners,
incontinence devices, and the like. More particularly, the present
invention relates to absorbent articles having flaps with a
deformed hinge and zones of extensibility for relieving the
stresses that develop in the flaps when they are folded down and
under a wearer's undergarment.
A preferred embodiment of a sanitary napkin 20 of the present
invention is shown in FIG. 1. As shown in FIG. 1, the sanitary
napkin 20 basically comprises an absorbent means (or "main body
portion") 22, and two flaps 24. The sanitary napkin 20 has two
surfaces, a body-contacting surface or "body surface" 20A and a
garment surface 20B. The sanitary napkin 20 is shown in FIG. 1 as
viewed from its body surface 20A. The body surface 20A is intended
to be worn adjacent to the wearers body. The garment surface 20B is
intended to be placed adjacent to the wearer's undergarments when
the sanitary napkin 20 is worn.
The sanitary napkin 20 has two centerlines, a principal
longitudinal centerline L and a principal transverse centerline T.
The term "longitudinal", as used herein, refers to a line, axis or
direction in the plane of the sanitary napkin 20 that is generally
aligned with (e.g., approximately parallel to) a vertical plane
which bisects a standing wearer into left and right body halves
when the sanitary napkin 20 is worn. The terms "transverse" or
"lateral" used herein, are interchangeable, and refer to a line,
axis or direction which lies within the plane of the sanitary
napkin 20 that is generally perpendicular to the longitudinal
direction.
FIG. 1 shows that the main body portion 22 of the sanitary napkin
20 comprises the portion of the sanitary napkin without the flaps
24. The main body portion 22 has two spaced apart longitudinal
edges 26, two spaced apart transverse or end edges (or "ends") 28,
which together form the periphery 30 of the main body portion. The
main body portion 22 also has two end regions, which are designated
first end region 32 and second end region 34. A central region 36
is disposed between the end regions 32 and 34. The end regions 32
and 34 extend outwardly in the longitudinal direction from the
edges of the central region 36 about 1/8 to about 1/3 of the length
of the main body portion. A detailed description of the
characteristics of a central region and two end regions for a
sanitary napkin is contained in U.S. Pat. No. 4,690,680 issued to
Higgins on Sep. 1, 1987.
The main body portion 22 of the sanitary napkin 20 can be of any
thickness, including relatively thick, intermediate thickness,
relatively thin, or even very thin (or "ultra thin"). An
"ultra-thin" sanitary napkin 20 as described in U.S. Pat. Nos.
4,950,264 and 5,009,653 issued to Osborn preferably has a caliper
of less than about 3 millimeters. The embodiment of the sanitary
napkin 20 shown in the drawings is intended to be an example of a
sanitary napkin of an intermediate thickness. The main body portion
22 of the sanitary napkin 20 may also be relatively flexible, so
that it is comfortable for the wearer. It should be understood that
the sanitary napkin shown is merely one embodiment, and that the
present invention is not limited to absorbent articles of the type
or having the specific configurations shown in the drawings.
FIG. 2 shows the individual components of the main body portion 22
of the sanitary napkin 20 of the present invention. The main body
portion 22 of the sanitary napkin preferably comprises at least
three primary components. These include a liquid pervious topsheet
38, a liquid impervious backsheet 40, and an absorbent core 42
positioned between the topsheet 38 and the backsheet 40. The
topsheet, the backsheet, and the absorbent core may be assembled in
a variety of configurations known in the art (including layered or
"sandwich" configurations and wrapped or "tube"
configurations).
Suitable materials for the components of the main body portion 22,
and some of the various configurations in which such components can
be assembled are described generally in U.S. Pat. No. 4,321,924,
"Bordered Disposable Absorbent Article" issued to Ahr on Mar. 30,
1982; U.S. Pat. No. 4,425,130, "Compound Sanitary Napkin" issued to
DesMarais on Jan. 10, 1984; U.S. Pat. No. 4,950,264, "Thin,
Flexible Sanitary Napkin" issued to Osborn on Aug. 21, 1990: U.S.
Pat. No. 5,308,346, "Elasticized Sanitary Napkin" issued to
Sneller, et al. on May 3, 1994; and U.S. Pat. No. 5,389,094
"Absorbent Article Having Flaps and Zones of Differential
Extensibility" issued to Lavash, et al. on Feb. 14, 1995. The main
body portion 22 of the sanitary napkin may also be comprised of one
or more extensible components such as those sanitary napkins, and
the like described in U.S. patent application Ser. Nos. 07/915,133
and 07/915,284, both filed Jul. 23, 1992, in the name of Osborn, et
al. (PCT Publication Nos. WO 93/01785 and 93/01786, both published
Feb. 4, 1993).
FIGS. 1-3 show a preferred embodiment of the sanitary napkin 20
assembled in a sandwich construction in which the topsheet 38 and
the backsheet 40 have length and width dimensions generally larger
than those of the absorbent core 42. The topsheet 38 and the
backsheet 40 extend beyond the edges of the absorbent core 42 to
form portions of the periphery 30. The topsheet 38 is preferably
joined to the body-facing side of the absorbent core 42 and the
backsheet 40 is preferably joined to the garment-facing side of the
absorbent core. The topsheet 38 and backsheet 40 can be joined to
the absorbent core in any suitable manner known in the art for this
purpose, such as by an open pattern of adhesives. The portions of
the topsheet 38 and backsheet 40 that extend beyond the edges of
the absorbent core are preferably also joined to each other. The
topsheet 38 and backsheet 40 can be joined in any suitable manner
known in the art for this purpose. Preferably, in the embodiment
shown, these portions of the topsheet 38 and backsheet 40 are
joined using adhesives over substantially the entire portions that
extend beyond the edges of the absorbent core 42, and a crimp seal
at the end edges 28 of the main body portion where the topsheet 38
and backsheet 40 are densified by the application of pressure or
heat and pressure.
The sanitary napkin 20 shown in FIGS. 1-3, as discussed above, also
comprises a pair of flaps 24 that are joined to the main body
portion 22. The flaps 24 extend laterally outward beyond the
longitudinal side edges 22 of the main body portion 22 from their
proximal edges 44 to their distal edges (or "free end") 46. The
flaps 24 extend outward from at least the central region 36 of the
main body portion 22. As shown in FIG. 1, each flap 24 is divided
into a front half 48, and a back half 50 by a flap transverse
centerline T.sub.1. The flap transverse centerline T.sub.1 may
coincide with the principal transverse centerline T of the sanitary
napkin, but this is not absolutely required.
The flaps 24 can be joined to th e main body portion 22 in any
suitable manner. The term "joined", as used herein, encompasses
configurations in which an element is directly s e cured to another
element by affixing the element directly to the other element;
configurations in which the element is indirectly secured to the
other element by affixing the element to intermediate member(s)
which in turn are affixed to the other element; and configurations
in which one element is integral with another element, i.e., one
element is essentially part of the other element. Preferably, in
the embodiment shown in FIGS. 1-3, the flaps 24 are integral with
the main body portion 22 (that is, the flaps 24 comprise integral
extensions of the topsheet 38 and backsheet 40).
In other alternative embodiments, the flaps 24 can comprise one or
more separate components that are joined to the garment-facing side
of the main body portion 22. Preferably, in such a case, the flaps
24 each comprise a separate component that is joined to the
garment-facing side of the main body portion 22. In such
alternative embodiments, the flaps 24 are preferably otherwise
unattached to the garment-facing side of the main body portion 22
of the sanitary napkin 20 between the points where they are
attached to the main body portion and the longitudinal side edges
26 of the main body portion. The flaps 24 in these latter
embodiments can be joined to the garment-facing side of the main
body portion 22 by any suitable attachment mechanism. Suitable
attachment mechanisms include, but are not limited to adhesives,
and the like.
The flaps 24 are each joined to (or associated with) main body
portion 22 along a juncture. This is typically a
longitudinally-oriented (or "longitudinal") juncture, such as lines
of juncture 52. As used herein, the terms "juncture" (or "line of
juncture") refer to regions where the flaps 24 extend from or are
join ed to the main body portion 22. These regions can be any of
various curved or straight lines, but they are not limited to
lines. Thus, these regions can comprise flanges, strips,
intermittent lines, and the like. The line of juncture 52 in the
embodiment illustrated in FIG. 1 can be considered to be defined by
concave inwardly-oriented regions or lines if the proximal edges 44
of the flaps 24 are considered to coincide with the inwardmost
boundary of the hinge 54 (described below).
The sanitary napkin 20 shown in FIGS. 1-3 preferably has a deformed
region that forms a hinge 54 between the main body portion 22 and
at least a portion of the flaps 24. The sanitary napkin 20
preferably also has at least one zone of extensibility (or "zone of
differential extensibility") 56 for relieving the stresses on the
flaps 24 when they are folded around a panty crotch. These are each
described below.
In the sanitary napkin shown in FIGS. 1-3, the hinge 54 comprises a
generally longitudinally-oriented, mechanically-deformed region.
The hinge 54 provides a region of the sanitary napkin 20 with
increased flexibility to create preferred bending axes for the
flaps 24 to bend or fold about. The hinge 54 is preferably located
in a region along the juncture 52 of the flaps 24 with the main
body portion 22. The hinge 54, however, does not have to coincide
exactly with the juncture 52 of the flaps 24 with the main body
portion 22. The hinge 54 can be located laterally inboard of the
juncture 52 of the flaps with the main body portion 22, on the
juncture, laterally outboard of the juncture, or any combination of
the foregoing. If the hinge 54 is located laterally inboard of the
juncture or on the juncture, the hinge 54 may be considered to be
formed in at least part of the main body portion 22 (and, in the
latter case, also in part of the flaps 24).
The hinge 54 can extend along the entire juncture 52 of the flaps
with the main body portion, or along only a portion thereof If the
hinge 54 is only provided along a portion of the juncture 52, it is
preferably provided in the region of the sanitary napkin 20
surrounding and including the flap transverse centerline. The hinge
54 can be in many possible configurations. The hinge 54 can
comprise a continuous region, or a plurality of spaced apart
intermittent regions. The hinge 54 can be rectilinear, curvilinear,
or it can comprise portions that are rectilinear and portions that
are curvilinear. The hinge 54 has a laterally inwardmost, or
proximal, boundary 54A and an outermost, or distal, boundary 54B.
In the embodiment shown in FIGS. 1-3, at least the inwardmost
boundary 54A of the hinge 54 is preferably concave inwardly
relative to the distal edge of the flaps 54.
The hinge 54 can be formed in any suitable manner that provides the
desired region of the sanitary napkin with increased flexibility.
Preferably, the hinge 54 is formed by mechanically deforming the
desired regions of the sanitary napkin. It has been found that many
processes suitable for providing regions of the sanitary napkin
with extensibility are particularly suitable for providing regions
of the sanitary napkin 20 selected for the hinge 54 with enhanced
flexibility.
The hinge 54 can, for instance, be formed by a process which has
been described as pre-corrugating (or "ring rolling"). Suitable
methods for ring rolling are described in U.S. Pat. No. 4,107,364
issued to Sisson on Aug. 15, 1978, U.S. Pat. No. 4,834,741 issued
to Sabee on May 30, 1989, U.S. Pat. NO. 5,143,679 issued to Gerald
M. Weber, et al. on Sep. 1, 1992, U.S. Pat. No. 5,156,793 issued to
Kenneth B. Buell, et al. on Oct. 20, 1992, and U.S. Pat. No.
5,167,897 issued to Gerald M. Weber, et al. on Dec. 1, 1992.
Alternatively, as shown in FIG. 1 for purposes of illustration, the
hinge 54 is provided by forming a strainable network in the region
along the juncture 52 of the flaps 24 with the main body portion
22. The process for forming a strainable network region, and
structures formed thereby are described in greater detail below in
conjunction with FIGS. 5-8. This technology is further described in
allowed U.S. Pat. No. 5,518,801 issued to Chappell, et al. on May
21, 1996 (PCT Publication No. WO 95/03765, published Feb. 9,
1995).
These structures (ring rolled structures and materials with
strainable network regions formed therein) are especially preferred
for the hinge 54 because the alternating ridges and valleys can
form a plurality of flexible bending axes for the flaps 24. These
types of structures also provide the hinge 54 with a degree of
extensibility. The extensibility allows the portions of the flaps
24 in the hinge region 54 to expand slightly in the transverse
direction to better fold around the curved sides of the wearer's
panty crotch. Providing the hinge 54 by forming strainable network
regions in the sanitary napkin may also be preferred when it is
desired to provide the formed regions with slightly more integrity
so the flaps 24 will be less likely to droop excessively at the
hinge 54 because the unformed first regions or less extensible
bands 64 (described below) of the strainable network will serve
like "beams" that tend to provide the flaps 24 with slightly more
structural rigidity and better appearance.
The process of forming a strainable network is preferred for
providing the sanitary napkin 20 with a hinge 54 because (like ring
rolling) such an operation can be readily adapted for use in high
speed manufacturing operations. Further, the process of forming a
strainable network in a material is highly preferred because it can
be adapted to produce a virtually unlimited number of patterns to
tailor the configuration and characteristics of the hinge 54 and
zones of extensibility 56.
Typically, the base material into which the strainable network is
formed comprises a single layer of material or laminate of
materials, at least one of which is a film. Preferably, in the
embodiment shown in FIGS. 1-3, the material that has the stainable
network formed therein comprises a laminate formed by an extension
of the topsheet and backsheet 40 of the sanitary napkin. The
topsheet 38 preferably comprises an apertured formed film made in
accordance with U.S. Pat. Nos. 4,342,314, Radel, et al. and
4,463,045, Ahr, et al. which is marketed on sanitary napkins as
DRI-WEAVE topsheet by The Procter & Gamble Company. The
backsheet 40 preferably comprises a polyethylene film. The two
components are preferably laminated together by adhesives.
The characteristics of the strainable network 62 in the hinge 54 of
the sanitary napkin shown in FIGS. 1-3 will be discussed with
reference to FIGS. 5-8. FIGS. 5-8 are enlarged views of a
simplified version of a web material 60 having a strainable network
62 formed therein. The tern "strainable network", as used herein,
refers to an interconnected and interrelated group of regions which
are able to be extended to some useful degree in a predetermined
direction. FIGS. 5 and 6 show the web material 60 in an untensioned
condition. The strainable network 62 comprises at least two
distinct and dissimilar regions which are designated as first
region 64 and second region 66.
In the simplified embodiment shown in FIGS. 5 and 6, the web
material 60 includes a plurality of first regions 64 and a
plurality of second regions 66. As shown in FIGS. 5 and 6, the
first regions 64 are substantially planar regions. That is, the
material within the first region 64 is in substantially the same
condition before and after the formation step undergone by web
material 60. The second regions 66 include a plurality of
continuous, interconnected, rib-like deformations 74 which extend
alternately beyond the plane of both the first and second surfaces
(64A and 64B, respectively) of the first region 64. In other
embodiments, the deformations 74 may extend beyond the plane of
only one of the first 64A or the second 64B surfaces of the first
region 64.
FIG. 5 shows that the web material 60 having the strainable network
62 formed therein has a longitudinal centerline (or axis), 1, and a
lateral centerline (or axis), t. In the sanitary napkin embodiment
shown in FIG. 1, the longitudinal centerline, 1, of the strainable
network 62 is shown as being rectilinear and generally oriented in
the transverse direction. However, the longitudinal centerline, 1,
is not limited to such a configuration and orientation. The
longitudinal centerline, 1, can be rectilinear, curvilinear, or
partially rectilinear and partially curvilinear. The longitudinal
centerline, 1, of the strainable network 62 can also be oriented in
other directions, if desired.
FIG. 5 shows that the first regions 64 of the strainable network 62
have a first axis 68 and a second axis 69, wherein the first axis
68 is preferably longer than the second axis 69. In the simplified
embodiment shown, the first axis 68 of the first region 64 is
substantially parallel to the longitudinal axis, 1, of the web
material 60 while the second axis 69 is substantially parallel to
the transverse axis, t, of the web material 60. The second regions
66 of the strainable network 62 also have a first axis 70 and a
second axis 71. The first axis 70 of the second region 66 is
substantially parallel to the longitudinal axis 1 of the web
material 60, while the second axis 71 is substantially parallel to
the transverse axis 1 of the web material 60. In the version of the
web material shown in FIGS. 5 and 6, the first regions 64 and the
second regions 66 are substantially linear, extending continuously
in a direction substantially parallel to the longitudinal axis 1 of
the strainable web material. In other embodiments, the second
regions 66 can be curvilinear, or partially rectilinear and
partially curvilinear.
While the enhanced flexibility of the strainable network is of
primary interest in forming the hinge 54, the strainable network
also provides portions of the flaps 24 with a degree of
extensibility. FIGS. 6-8 show the manner in which the web material
60 with a strainable network 62 formed therein may exhibit at least
two significantly different stages of controlled resistive force to
elongation when subjected to an applied elongation in a direction
parallel to a predetermined axis. The strainable network 62
exhibits first resistive forces to the applied elongation (which
develop between the stage shown in FIG. 6 and the stage shown in
FIG. 7). The first resistive forces occur until the elongation of
the web is sufficient to cause a substantial portion of the second
regions 66 to enter the plane of applied elongation, as shown in
FIG. 7. After the web material 60 reaches the stage shown in FIG.
7, it exhibits second resistive forces to further elongation (as
illustrated by FIG. 8). Typically, when used in regions of the
sanitary napkin 20 described herein, the web material will be
within the firs t stage of resistance to elongation so the various
portions of the strainable network 62 will only extend to the stage
shown in FIG. 7 and adjust so as to relax back to the stage shown
in FIG. 6.
The hinge 54 is created by forming the strainable network 62 into
the desired portion of the sanitary napkin 20. As used herein, the
term "forming" refers to the creation of a desired structure or
geometry upon a web material or laminate that will substantially
retain the desired structure or geometry when it is not subjected
to any externally applied elongations or forces. Suitable methods
for forming a strainable network into a web material include, but
are not limited to embossing by mating plates or rolls,
thermoforming, high pressure hydraulic forming, and casting.
The portion of the sanitary napkin 20 into which the strainable
network 62 is formed can comprise a base material (or laminate)
that has a relatively low extensibility under the forces that the
sanitary napkin is normally subjected to when worn. When the
strainable network 62 is formed therein, however, the base material
can be made extensible under pre-selected forces such as those that
the sanitary napkin is normally subjected to when worn.
The depth and number of deformations 74 in the strainable network
62 can be varied to control the applied force or elongation
required to extend the material in the hinge regions 54 of the
sanitary napkin 20. In one embodiment, the deformations 74 may be
formed by two rigid plates having a pattern of meshing teeth. The
outer dimensions of the pattern of teeth covers a surface area of
the plates that is about 7.9" by 1.6" (20 cm by 4 cm) for each
flap. On one surface of each plate are a series of teeth which are
substantially triangular in cross section and taper to a radiused
vertex. The teeth in this embodiment preferably have a height of
3.175 mm, and are evenly spaced with the centerlines of the teeth
spaced apart at 0.075" (1.9 mm) increments. On the "toothed" side
of one plate, a series of grooves (preferably three grooves to
construct the embodiment shown in FIG. 1) are cut which are
parallel to each other and perpendicular to the evenly spaced
teeth. These grooves correspond to the undeformed regions of the
base material.
The preferred base material is placed between the plates in a
hydraulic press having platens larger than the plates to evenly
distribute pressure. The plates are compressed so that the teeth
only partially engage (or mesh). Preferably, the plates are moved
so that the teeth on the opposite plates are pressed toward each
other about 80% of the distance toward full engagement (the point
where the teeth would otherwise touch). Typically, in order to do
this, when the base material comprises a laminate of apertured
formed film and polyethylene backsheet material laminated together
by adhesives that is described in conjunction with the embodiment
shown in FIGS. 1-3, the plates will be compressed under a load of
between about 25-70 psi. (about 1,750-4,900 g/cm2). The formed web
material is then removed from between the plates. In the embodiment
shown in FIGS. 1-3, the formed web material is provided with about
75% extensibility. The available stretch or elongation is increased
if for a given number of deformations, the height or degree of
deformation imparted to the web material is increased. Similarly,
the available stretch or elongation is increased if for a given
height or degree of deformation, the number or frequency of
deformations is increased. The mating plates can be configured to
create any of the patterns for the hinge 54 on the sanitary napkins
shown in the drawings.
The sanitary napkin also has zones of extensibility 56 for
relieving the stresses that develop in the flaps when they are
folded down and under a wearer's undergarment. The terms "zone of
extensiblity" or "zone of differential extensibility", as used
herein, refer to a portion of the sanitary napkin 20 which is
capable of extending (and are preferably capable of extending a
greater amount than surrounding portions of the sanitary napkin
20). The sanitary napkin 20 preferably has at least one zone of
extensibility 56 for each flap 24, and more preferably has four
zones of extensibility 56, one in each quarter of the sanitary
napkin 20. Since the zones of differential extensibility 50 relieve
stresses in the flaps, they may be referred to herein as a type of
"stress relief means".
The zones of extensibility 56 can be extensible in any desired
direction, or in more than one direction. However, the zones of
extensibility 56 are preferably primarily extensible generally
outward in the transverse direction. This is generally in the
direction of the arrows shown in FIG. 1. As used herein, "generally
in the transverse direction" means that the extensibility has a
transverse component. All of the extension, however, need not be
exactly parallel to the principal transverse centerline of the
sanitary napkin. The extensibility, however, is preferably oriented
more in the transverse direction than in the longitudinal
direction.
The zones of extensibility 56 can comprise any structure capable of
extending in the transverse direction (or in any other direction
desired). The extensibility referred to herein, however, should be
elasticless. That is, it should be accomplished without the use of
separate elastic pieces, strands, or materials to contract one or
more portions of the sanitary napkin. The zones of extensibility
must also be accomplished without slitting or notching portions of
the sanitary napkin that cover the wearer's undergarments. The
zones of extensibility 56, therefore, comprise continuous material.
This will have the advantage that exudates will not be able to
travel through the slits or notches to soil the wearer's
undergarments.
Suitable structures for the zones of extensibility 56 include, but
are not limited to zones of material that are mechanically
strained, corrugated, "ring rolled", formed with a strainable
network therein, formed with a network of corrugations without any
less extensible bands therein, folded, pleated, or joined along a
curved juncture. These structures (although shown only as being
part of the flaps 24), can comprise portions of the main body
portion 22, portions of the flaps 24, or both. They can be integral
parts of these components of the sanitary napkin, or separate
elements, such as pieces of material, joined to the sanitary
napkin. Suitable structures for the zones of extensibility are
described in greater detail in U.S. Pat. No. 5,389,094 issued to
Lavash, et al. on Feb. 14, 1995.
In the embodiment shown in FIG. 1, the zones of extensibility 56
can either comprise ring rolled regions of the flaps or a network
of corrugations without, any less extensible bands therein. In
either case, the zones of extensibility 56 preferably have
corrugations with ridges that are oriented generally in the
longitudinal direction so that the zones of extensibility will be
extensible primarily in the transverse direction.
There are many possible arrangements and configurations that the
zones of extensibility 56 may have relative to each other and
relative to the hinges 54. The zones of extensibility 56 (or at
least portions thereof) are preferably spaced longitudinally away
from the flap transverse centerline T1. As shown in FIG. 1, the
portions of the zones of extensibility 56 that are spaced laterally
furthest outward from the juncture 52 of the flaps 24 with the main
body portion 22 are separated by an intermediate region 58. The
portions of the zones of extensibility 56 that are closest to the
juncture 52 of the flaps 24 with the main body portion 22 can also
be spaced longitudinally away from the flap transverse centerline
T1 so that they do not abut each other. Alternatively, these
portions of the zones of extensibility 56 can abut each other.
The intermediate region 58 comprises a region of the flap 24 that
includes the flap transverse centerline T1 and laterally adjacent
regions. The intermediate region 58 is preferably stiffer than the
regions of the sanitary napkin that comprise the hinge 54 and the
zones of extensibility 56. This provides the flaps 24 with more
integrity so that they will be easier for the user to handle. Thus,
the main body portion 22 of the sanitary napkin is preferably the
stiffest portion of the sanitary napkin. The intermediate region 58
is preferably the stiffest portion of the flaps 24, and is
preferably not as stiff as the main body portion 22. The hinge 54
is preferably more flexible than either of those portions of the
sanitary napkin.
The zones of extensibility 56 can be spaced away from the hinge 54,
or be adjacent to the hinge 54. Preferably, as shown in FIG. 1, the
hinge 54 is contiguous (that is, touching or connected throughout
in an unbroken sequence) with the zones of extensibility 56. The
hinge 54 and the preferred ring rolled zones of extensibility 56
are, thus, portions of a continuous composite deformed region. As
shown in FIG. 1, the hinge 54 gradually transitions into portions
of the sanitary napkin that comprise the zones of extensibility 56.
The composite deformed region, thus, comprises continuous
corrugations having ridges that are generally oriented in the
longitudinal direction with a plurality of inextensible bands 64 in
the center region adjacent the flap transverse centerline T1.
As shown in FIG. 1, the composite deformed region preferably has a
proximal boundary along the juncture 52 of the flaps 24 with the
main body portion 22 that is concave relative to the distal edges
46 of the flaps 24. The composite deformed region preferably has a
distal boundary that is also concave relative to the distal edges
46 of the flaps. FIG. 1 shows that the distal boundary of the
composite deformed region defines the boundary of the intermediate
region 58 as a generally semi-circular area. Further, as shown in
FIG. 1, the radius of curvature of the distal boundary of the
composite deformed region is preferably less than the radius of
curvature of the proximal edge of the composite deformed
region.
Many variations of the embodiments described herein are possible.
For example, instead of comprising corrugations with linear ridges
that are oriented in the longitudinal direction, the deformations
forming these regions can be arranged in the form of a series of
concentric concave ridges and valleys that are aligned with the
boundaries of these regions. In another example, instead of being a
contiguous composite deformed region, the hinge 54 and the zones of
extensibility 56 may be separate spaced apart structures.
Alternatively, the hinge 54 and/or the zones of extensibility 56,
instead of comprising deformed regions of the sanitary napkin, can
comprise some other suitable type of structure that provides the
sanitary napkin with the desired properties of increased
flexibility and extensibility in these regions. The main body
portion 22 of the sanitary napkin 20 can also comprise a pair of
embossed channels as described in U.S. Pat. No. 5,308,346 issued to
Sneller, et al. The features shown and described herein for the
various embodiments can also be combined in any other suitable ways
to form still more alternative embodiments.
The garment surface 20B of the sanitary napkin 20 may include, and
preferably does include, fasteners for attaching the sanitary
napkin to the wearer's undergarment. FIG. 1 shows the central pad
fastener 80 which is adapted to secure the main body portion 22 of
the sanitary napkin to the crotch region of an undergarment. Any
types of fasteners known in the art, such as adhesive fasteners and
mechanical fasteners can be used. Fasteners comprising adhesives
have been found to work well for this purpose, with
pressure-sensitive adhesives being preferred. FIG. 1 shows a
preferred arrangement which utilizes a pair of spaced apart
longitudinally-oriented strips or zones of adhesive 80 that are
centered about the longituded centerline L.
The outer surface of the flaps 24, adjacent the distal edges 46 of
the flaps, is preferably provided with a flap adhesive 82. The flap
adhesive 82 is used to assist in maintaining the flaps 24 in
position after they are wrapped around the edge of the crotch
portion of the panty. Suitable adhesive fasteners are described in
greater detail in U.S. Pat. No. 4,917,697. The flaps 24 can be
maintained in position by attaching the flaps 24 to the
undergarment, or to the opposing flap.
The fasteners used with the present invention are not limited to
adhesive attachment means. Any type of fastener used in the art can
be used for such purpose. For example, the sanitary napkin 20 could
be secured to the wearer's undergarment by mechanical fasteners,
such as VELCRO, or the fasteners described in U.S. Pat. No.
4,946,527 entitled "Pressure-Sensitive Adhesive Fastener and Method
of Making the Same" issued to Battrell on Aug. 7, 1990, or U.S.
Pat. No. 5,392,498 entitled "Non-Abrasive Skin Friendly Mechanical
Fastening System" issued to Goulait, et al. on Feb. 28, 1995. For
simplicity, however, the fasteners will be described in terms of
adhesive attachment means.
The adhesive attachment means are respectively covered by removable
release liners, central pad release liner and flap release liner,
both designated 84. The pressure-sensitive adhesives should be
covered with release liners 84 to keep the adhesives from sticking
to extraneous surfaces prior to use. Suitable release liners are
described in U.S. Pat. No. 4,917,697. A particularly preferred
release liner which also serves as an individual package for
wrapping the sanitary napkin is described in U.S. Pat No. 4,556,146
issued to Swanson, et al. In other embodiments, the flaps 24 could
be folded and tucked as described in U.S. Pat. No. 5,281,209 issued
to Osborn, et al. on Jan. 25, 1994. The adhesive attachment means
on such flaps could, instead of being covered with a release liner,
be releasably adhered to a release surface provided on some other
portion of the sanitary napkin, including the main body portion, or
the flaps, or a separate component attached to the main body
portion or the flaps.
The sanitary napkin 20 of the present invention is utilized by
removing the release liners 84 and placing the sanitary napkin 20
in a panty 11 as shown in FIG. 4 The main body portion 22 is placed
in the crotch portion of the panty with one end of the main body
portion 22 extending towards the front section of the panty and the
other end towards the back section of the panty. The backsheet 40
is placed in contact with the inner surface of the center of the
crotch portion of the panty. The central pad adhesive fastener 80
maintains main body portion 22 in position. The distal portions of
the flaps 24 are folded around the side edges 16 of the panty. The
flap adhesives 82 secure the flaps 24 to the underside of the panty
or to the opposing flap.
Other embodiments of the absorbent articles are also possible. For
example, in alternative embodiments, instead of being provided with
flaps, the absorbent article could be provided with undergarment
covering components or ("side wrapping elements") that have a
smaller span than conventionally sized flaps and that do not have
to be manipulated by the wearer when placed in the wearer's
undergarments. Absorbent articles having side wrapping elements are
described in U.S. patent application Ser. No. 08/096,121 entitled
"Absorbent Articles Having Panty Covering Components That Naturally
Wrap the Sides of Panties" filed Jul. 22, 1993, in the name of
Lavash, et al. (PCT Publication No. WO 94/02096, published Feb. 3,
1994); U.S. patent application Ser. No. 08/124,180 entitled
"Absorbent Articles Having Panty Covering Components Comprising
Extensible Web Materials Which Exhibit Elastic-Like Behavior" filed
Sep. 17, 1993, in the name of Mansfield, et al. (PCT Publication
No. WO 95/07675, published Mar. 23, 1995); and U.S. patent
application Ser. No. 08/277,733 entitled "Absorbent Articles Having
Undergarment Covering Components With Zones of Extensibility" filed
Jul. 20, 1994 in the name of Weinberger, et al. (PCT Publication
No. WO 95/03025, published Feb. 2, 1995).
The disclosures of all patents, patent applications (and any
patents which issue thereon, as well as any corresponding published
foreign patent applications), and publications mentioned throughout
this patent application are hereby incorporated by reference
herein. It is expressly not admitted, however, that any of the
documents incorporated by reference herein teach or disclose the
present invention. It is also expressly not admitted that any of
the commercially available materials or products described herein
teach or disclose the present invention.
While particular embodiments of the present invention have been
illustrated and described, it would be obvious to those skilled in
the art that various other changes and modifications can be made
without departing from the spirit and scope of the invention.
* * * * *